JP2005110543A - Hydrogen-producing apparatus and hydrogen-producing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a hydrogen-producing treatment using anaerobic microorganisms. <P>SOLUTION: The hydrogen-producing apparatus 100 comprising organic wastes 103, a treating tank 102 for receiving anaerobic microorganisms (not displayed) for degrading the organic wastes 103 to produce the hydrogen, and a hydrogen-recovering portion 130 for recovering the hydrogen produced in the treating tank 102, is characterized by disposing a ventilation hole 105 in the treating tank 102 to open the treating tank 102. The hydrogen-producing apparatus 100 further has a gas trap 104 disposed in the treating tank 102. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a hydrogen generator and a hydrogen generation method.

  As the scale of global industrial economic activity has increased in recent years, environmental destruction at the global level has become an important issue. In particular, there is concern that the global warming problem will have a significant adverse effect not only on humankind but also on the earth itself. Since the direct cause of global warming is an increase in carbon dioxide emissions associated with the burning of large amounts of fossil fuels in recent years, there is an urgent need to continuously reduce carbon dioxide emissions on a global scale. . In addition, with the increase in organic waste in recent years, the problem of generation of harmful substances such as carbon dioxide and dioxin accompanying the incineration process has become serious, and an immediate countermeasure is desired.

  However, since the increase in carbon dioxide emissions is the result of many years of economic activity, the accepted method of reducing carbon dioxide emissions must be a method that does not impede current economic activity.

  Therefore, it has become necessary to search for new technologies that suppress the release of carbon dioxide, to create energy sources such as hydrogen using biological functions, and to fix and decompose carbon dioxide. Above all, hydrogen can be converted into electric energy with high efficiency as a fuel cell, the calorific value is 3 to 4 times that of petroleum, and only water is produced after combustion, so there are no negative effects on the environment. Has the advantage of

Patent Document 1 discloses a biogas generator that generates hydrogen by anaerobic fermentation. In such a biogas generator, acetic acid, carbon dioxide, and hydrogen are generated based on the following chemical formula (1) by the action of anaerobic microorganisms.
_{C 6 H 12 O 6 + 2H} 2 O → 2CH 3 COOH + 2CO 2 + 4H 2 (1)
JP 2001-149983 A

  By the way, conventionally, in an apparatus using such anaerobic fermentation, the inside of the fermenter is depressurized or carbon dioxide is blown into the fermenter to artificially make the fermenter anaerobic and generate hydrogen. It was. However, when the reaction of the above chemical formula (1) is performed, hydrogen and carbon dioxide are generated, and the inside of the tank is naturally anaerobic due to the action of the microorganism itself. Therefore, by using a facultative anaerobic microorganism that can decompose organic waste even if it is not completely anaerobic, it does not take labor and cost to artificially make the tank anaerobic. Also, the reaction of the chemical formula (1) can be promoted.

  In addition, if the hydrogen partial pressure in the tank is too high, there is a problem that hydrogen fermentation is inhibited by the biotoxin action of hydrogen.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a hydrogen generation apparatus and a hydrogen generation method for generating hydrogen by a simple process. Another object of the present invention is to increase the efficiency of hydrogen generation.

  According to the present invention, an organic substance, a treatment tank containing anaerobic microorganisms that decompose the organic substance to generate hydrogen, and a recovery means for recovering hydrogen generated in the treatment tank are provided, and the treatment tank is opened. A hydrogen generator characterized by being made into a system is provided.

  Here, being made open means that it is communicated with the outside by some means. According to the hydrogen generator of the present invention, it is possible to save the trouble of artificially anaerobic the inside of the treatment tank. In addition, by making the treatment tank open, hydrogen generated in the treatment tank that has not been recovered by the recovery means can be discharged outside the treatment tank, and the hydrogen partial pressure in the treatment tank is lowered. be able to. Thereby, inhibition of hydrogen fermentation due to the catalytic poisoning effect of hydrogen can be prevented. Therefore, hydrogen generation efficiency can be increased.

  As the anaerobic microorganism, a facultative anaerobic microorganism capable of decomposing organic matter even if it is not completely anaerobic can be used. Examples of such microorganisms include enterobacter such as cellulose-degrading bacteria (Paenibacillus (Bacillus) polymyxa), Penibacillus macerans, Enterobacter aerogenes and Enterobacter cloacae. Examples include genus bacteria, Escherichia coli, Klebsiella pneumoniae, Pseudomonas stutzeri, and the like.

  The organic matter can be organic waste such as waste water including garbage. By using organic waste, it is possible to produce hydrogen with high energy efficiency while suppressing costs. At the same time, the BOD (biochemical oxygen demand) in the waste water can be reduced. As a result, it is possible to reduce the load on the environment.

  In the hydrogen generator of the present invention, the recovery means can be a gas trap disposed in the treatment tank.

  By arranging the gas trap in the treatment tank, hydrogen generated in the treatment tank can be efficiently recovered.

  The hydrogen generator of the present invention may further include a guide member that is provided on the side wall of the processing tank and guides the hydrogen generated in the processing tank to the gas trap.

  By providing the guide member, hydrogen generated in the treatment tank can be efficiently recovered, and the hydrogen recovery rate can be increased.

  The hydrogen generator of the present invention may further include a vent opening the processing tank and a vent film provided in the vent hole.

  With such a configuration, the hydrogen partial pressure in the processing tank can be reduced, and even when the processing tank is an open system, it is possible to prevent dust, dust, and the like from entering the processing tank.

  According to the present invention, there is provided a hydrogen generation method characterized by comprising a step of decomposing organic matter to generate hydrogen in an open tank containing anaerobic microorganisms and a step of recovering hydrogen. Is done.

  According to the hydrogen generation method of the present invention, it is possible to save the trouble of artificially anaerobic the inside of the treatment tank. Moreover, the hydrogen partial pressure in a processing tank can be made low, and inhibition of hydrogen fermentation by the catalytic poisoning action of hydrogen can be prevented.

  ADVANTAGE OF THE INVENTION According to this invention, the hydrogen generator and the hydrogen generation method which generate | occur | produce hydrogen by simple process are provided. Moreover, according to the present invention, the efficiency of hydrogen generation can be increased.

FIG. 1 is a diagram showing a configuration of a hydrogen generator 100 according to an embodiment of the present invention.
In the present embodiment, the hydrogen generator 100 is configured to generate hydrogen by the action of anaerobic microorganisms and to recover the hydrogen. The hydrogen generator 100 includes a processing tank 102, a gas trap 104, a stirring body 106, an inlet 108, an outlet 110, a temperature adjustment unit 112, a pipe 114, and a roof 116.

  A facultative anaerobic microorganism (not shown) having hydrogen generation ability is introduced into the treatment tank 102. The facultative anaerobic microorganisms include the facultative anaerobic bacteria cellulolytic bacteria (Paenibacillus (Bacillus) polymyxa), Penibacillus macerans, Enterobacter aerogenes and Enterobacter cloacae ( Examples include Enterobacter cloacae and other Enterobacter bacteria, Escherichia coli, Klebsiella pneumoniae, Pseudomonas stutzeri, and the like. Further, together with facultative anaerobic microorganisms, absolute anaerobic bacteria such as Clostridium can be used in combination.

  In addition, the organic waste 103 is introduced into the treatment tank 102 from the inlet 108. The facultative anaerobic microorganisms decompose the organic waste introduced from the inlet 108 as shown in the chemical formula (1) to generate hydrogen. Further, the residue is discharged from the discharge port 110. In the hydrogen generator 100, the organic waste can be continuously introduced from the inlet 108, and the residue can be continuously discharged from the outlet 110 to perform continuous processing.

  The gas trap 104 captures a gas containing hydrogen generated in the treatment tank 102 and introduces the captured gas into the hydrogen recovery unit 130 via the pipe 114. The gas trap 104 has a function of sucking the gas with an appropriate attractive force so as to efficiently absorb the gas. For example, the gas trap 104 can be configured such that the pressure is lower than the pressure in the processing bath 102. The detailed configuration of the gas trap 104 will be described later.

  In addition, a vent 105 that opens the processing tank 102 is provided at the top of the processing tank 102. Hydrogen and other gases not recovered by the gas trap 104 are exhausted from the vent 105. Thereby, the hydrogen partial pressure in the processing tank 102 can be reduced. Moreover, the structure of the hydrogen generator 100 can be simplified by making the treatment tank 102 an open system. The ventilation hole 105 can be provided with a ventilation film such as a pore filter or a breathable cloth. Thereby, it is possible to prevent dust, dust and the like from entering the processing tank 102. In addition, when the treatment tank 102 is disposed outdoors, it is possible to prevent rainwater or the like from entering the treatment tank 102 by providing the roof 116. In the case where the treatment tank 102 is installed indoors or in a housing, the roof 116 may be omitted.

  The agitator 106 agitates the microorganisms and organic waste introduced into the treatment tank 102. Thereby, reaction by the microorganisms in the processing tank 102 can be performed equally efficiently. Further, hydrogen generated in the treatment tank 102 can be efficiently captured by the gas trap 104, and the hydrogen partial pressure in the treatment tank 102 can be lowered.

  Hydrogen generator 100 further includes pH sensor 118, temperature sensor 120, pH adjuster 122, pump 124, temperature adjuster 112, and controller 126. The pH sensor 118 measures the pH in the treatment tank 102. The temperature sensor 120 measures the temperature in the processing tank 102. These measurement results are input to the control unit 126. The pH adjusting unit 122 contains, for example, a pH adjusting solution, and is configured such that the pH adjusting solution is introduced into the processing tank 102 by controlling the pump 124. The temperature adjustment unit 112 is, for example, a heater or a cooler.

  The control unit 126 controls the pH adjusting unit 122 and the temperature adjusting unit 112 according to the pH and temperature in the processing tank 102, and appropriately maintains the pH and temperature in the processing tank 102. The pH and temperature in the treatment tank 102 are appropriately set depending on the type of microorganism to be used, and can be, for example, pH 5-6 and temperature 25 ° C-30 ° C. In addition, although demonstrated here that the control part 126 controls pH and temperature in the processing tank 102, of course, pH and temperature in the processing tank 102 can also be adjusted manually.

  FIG. 2 is a cross-sectional view showing the configuration of the gas trap 104. As shown in FIGS. 2A to 2C, the gas trap 104 is provided so as to be movable in the processing tank 102. Thereby, the position of the gas trap 104 can be changed according to the fermentation state by the microorganisms introduced into the processing tank 102. Although the adjustment of the position of the gas trap 104 can be performed manually, it can be configured to be controlled by the control unit 126.

  FIG. 3 is a cross-sectional view illustrating another example of the processing tank 102. In addition to the configuration shown in FIG. 1, the hydrogen generator 100 may further include a guide 132 that is provided on the side wall of the processing tank 102 and guides hydrogen generated in the processing tank 102 to the gas trap 104. Thereby, the clearance gap between the gas trap 104 and the wall surface of the processing tank 102 can be filled, and the hydrogen recovery rate can be increased.

  FIG. 4 is a cross-sectional view showing still another example of the processing tank 102. As shown in FIG. 4, the gas trap 104 may include a plurality of traps that are smaller than the size of the processing tank 102. Here, the small traps are distributed in the vertical direction and the horizontal direction in the processing tank 102. Further, these can be provided so as to be movable in the vertical direction and the horizontal direction in the treatment tank 102. In this way, hydrogen generated in the treatment tank 102 can be recovered uniformly, and the hydrogen recovery rate can be increased. In addition, since hydrogen that has not been recovered by the plurality of small traps can escape from these gaps and be released to the outside through the vent 105, the hydrogen partial pressure in the treatment tank 102 can be lowered.

FIG. 5 is a block diagram specifically illustrating an example of the configuration of the hydrogen recovery unit 130.
The gas containing hydrogen trapped by the gas trap 104 can be supplied to the fuel cell mainly through two paths described below.

  First, as a first path, gas is introduced into the dehydration processing unit 134. In the dehydration processing unit 134, moisture in the gas is removed by, for example, silica gel or sulfuric acid treatment. Next, the gas is introduced into the gas separation unit 136. In the gas separation unit 136, carbon dioxide and the like are removed. The gas separation unit 136 is provided with a gas separation membrane made of, for example, aromatic polyimide that can selectively separate hydrogen. Thereby, high purity hydrogen can be separated and obtained by the gas separation unit 136. In this way, hydrogen whose purity is increased is supplied to the fuel cell 138. Further, the hydrogen separated by the gas separation unit 136 can be compressed and filled in the hydrogen cylinder 140.

  As a second path, the hydrogen generated in the treatment tank 102 can be supplied to the fuel cell 138 after being reformed by the reformer 144 in the same manner as natural gas. In this case, the gas captured by the gas trap 104 is introduced into the gas pipe 142 of natural gas and introduced into the reformer 144 via the gas pipe 142. Note that the gas after passing through the dehydration processing unit 134 and the gas separation unit 136 described above may be introduced into the reformer 144.

  Further, the exhaust gas such as carbon dioxide separated from hydrogen by the gas separation unit 136 can be reintroduced into the upper portion of the gas trap 104 through the exhaust gas pipe 146. Thereby, the hydrogen partial pressure in the processing tank 102 can be reduced.

FIG. 6 is a diagram illustrating an example of a pretreatment unit that performs pretreatment of organic waste introduced into the hydrogen generator 100.
The pretreatment unit 1 includes a disposer 200, a precipitation separation tank 700, a solid-liquid separation device 400, and a compost device 600.

The pretreatment process will be described. In the pretreatment unit 1, the organic waste is separated into a solid content and a liquid content.
In the disposer 200, organic waste such as food waste (garbage) and waste water are introduced. The organic waste is pulverized by the disposer 200 and separated into a solid content and a liquid content by the precipitation separation tank 700 and the solid-liquid separation device 400. The liquid component (about BOD 5500 mg / L) is introduced into the hydrogen generator 100. On the other hand, the solid content is composted by the composting device 600 and used as, for example, compost.

  In place of the treatment by the disposer 200, a pulverization treatment, a low molecular weight treatment (heat, oxidative decomposition, etc.), etc. may be employed. Moreover, it is also possible to introduce into the hydrogen generator 100 the food waste made into a slurry by crushing and crushing without using the solid-liquid separator 400 in the pretreatment unit 1.

Next, a predetermined procedure of the hydrogen generator 100 in the present embodiment will be described with reference to FIG.
First, organic waste such as food waste is pretreated (S100). Subsequently, the pretreated organic waste is introduced into the treatment tank 102. In the treatment tank 102, facultative anaerobic microorganisms capable of generating hydrogen are introduced, and organic waste is decomposed by the action of the microorganisms. As shown in the chemical formula (1), hydrogen is absorbed. Is generated (S102). A gas containing hydrogen is captured by the gas trap 104, and the captured gas containing hydrogen is supplied to the fuel cell after the reforming process (S104) or without the reforming process (S106).

  In this example, an example is shown in which garbage is used as the organic waste and Enterobacter aerogenes is used as the microorganism.

  Generation of hydrogen was observed using the hydrogen generator 100 having the configuration shown in FIG. As the hydrogen recovery unit 130, the one having the configuration shown in FIG. 5 was used, and the gas that passed through the gas separation unit 136 was used as a measurement target.

As the medium, the following GP medium was used, and the pH was 6.0 and the temperature was 30 ° C.
GP medium (1 liter): glucose 10 g, polypeptone 20 g, KH ₂ PO ₄ 2 g, Yeast Extract 0.5 g, and MgSO ₄ .7H ₂ O 0.5 g

  As a result, hydrogen was efficiently recovered from the treatment tank 102.

It is a figure which shows the structure of the hydrogen generator in embodiment of this invention. It is sectional drawing which shows the structure of a gas trap. It is sectional drawing which shows the other example of a processing tank. It is sectional drawing which shows the other example of a processing tank. It is a block diagram which shows an example of a structure of a hydrogen collection | recovery part concretely. It is a figure which shows an example of the pre-processing part which performs the pre-processing of the organic waste introduce | transduced into a hydrogen generator. It is a flowchart which shows the predetermined procedure of a hydrogen generator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pretreatment part, 100 Hydrogen generator, 102 Processing tank, 103 Organic waste, 104 Gas trap, 105 Vent, 106 Stirrer, 108 Inlet, 110 Outlet, 112 Temperature control part, 114 Piping, 116 Roof , 118 pH sensor, 120 temperature sensor, 122 pH adjustment unit, 124 pump, 126 control unit, 130 hydrogen recovery unit, 132 guide, 134 dehydration processing unit, 136 gas separation unit, 138 fuel cell, 140 hydrogen cylinder, 142 gas pipe , 144 reformer, 200 disposer, 400 solid-liquid separation device, 600 composting device, 700 precipitation separation tank.

Claims (5)

A treatment tank containing organic matter and anaerobic microorganisms that decompose the organic matter to generate hydrogen;
Recovery means for recovering hydrogen generated in the treatment tank,
A hydrogen generator, wherein the treatment tank is an open system.   The hydrogen generation apparatus according to claim 1, wherein the recovery unit is a gas trap disposed in the processing tank.   The hydrogen generator according to claim 2, further comprising a guide member provided on a side wall of the processing tank and guiding hydrogen generated in the processing tank to the gas trap. A vent for opening the treatment tank;
A gas permeable membrane provided in the vent;
The hydrogen generator according to claim 1, further comprising: A process of decomposing organic matter in an open tank containing anaerobic microorganisms to generate hydrogen;
Recovering the hydrogen;
A hydrogen generation method comprising:

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